Wall block and wall block system for constructing walls

ABSTRACT

Wall blocks and methods of constructing walls from the wall blocks which have a side connection system interlocking adjacent blocks whereby a side of the block is provided with a channel or slot that is configured to engage a corresponding projection on the adjacent block. The side connection system may alternatively have a connection receiving cavity formed by channels or slots on the sides of the blocks which are configured to align with a channel or slot from adjacent blocks where a connector may be received to interlock the blocks.

This application is a continuation of U.S. Ser. No. 12/124,311, filedMay 21, 2008, which claims the benefit of U.S. Provisional ApplicationNo. 60/931,137, filed May 21, 2007, the contents of each of which arehereby incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates generally to wall blocks and walls constructedfrom such blocks. In particular, this invention relates to wall blockshaving cores, interlocking projections and slots, and curvilinearrecesses and walls made from such blocks. This invention also relates towall blocks having cores, curvilinear recesses and a side connectionsystem and the walls made from such blocks.

BACKGROUND OF THE INVENTION

Retaining walls and freestanding walls are used in various landscapingprojects and are available in a wide variety of styles. Numerous methodsand materials exist for the construction of retaining walls. Suchmethods include the use of natural stone, poured concrete, precastpanels, masonry, and landscape timbers or railroad ties.

In recent years, segmental concrete retaining wall units, which are drystacked (i.e., built without the use of mortar), have become widelyaccepted in the construction of retaining walls. An example of such aunit is described in U.S. Pat. No. Re 34,314 (Forsberg). Such retainingwall units have gained popularity because they are mass produced and,consequently, relatively inexpensive. They are structurally sound, easyand relatively inexpensive to install, and couple the durability ofconcrete with the attractiveness of various architectural finishes. Theretaining wall system described in U.S. Pat. No. Re 34,314 (Forsberg)has been particularly successful because of its use of a block designthat includes, among other design elements, a unique pinning system thatinterlocks and aligns the retaining wall units, thereby providingstructural strength and allowing efficient installation. This system isadvantageous in the construction of larger walls, when combined with theuse of geogrids hooked over the pins, as described in U.S. Pat. No.4,914,876 (Forsberg). However, in smaller walls, for example, walls ofthree foot height or less this connection system of interlocking pins isunnecessary for wall stability and adds to the cost of the system andcomplexity of wall construction.

Another important feature of retaining wall blocks and blocks used infree standing walls is the appearance of the block. The look ofweathered natural stone is very appealing for walls. There are severalmethods in the art to produce concrete wall blocks having an appearancethat to varying degrees mimics the look of natural stone. One well knownmethod is to split the block during the manufacturing process so thatthe front face of the block has a fractured concrete surface that lookslike a natural split rock. This is done by forming a slab in a mold andproviding one or more grooves in the slab to function as one or moresplitting planes. The slab is then split apart to form two or moreblocks. Another method is wherein blocks are individually formed in amold and the surfaces are textured by removal of the mold. Additionalmachine texturing processes can then be applied. Many manufacturers alsovary the color and the texture or pattern on the front face of theblock. It might be desirable for the face of the block to be smooth,serrated, or grooved or to have an aggregate appearance.

Another method to create a weathered stone appearance is to tumble theblocks together with other blocks in a large rotating canister. Thecollisions of the blocks in the tumbler chips off random pieces of theblocks, rounding the edges and creating a look that can be quite closeto the appearance of a natural stone. This is a labor intensiveundertaking that also can result in undesirable damage to the blocks andhigh overall costs of production.

Many manufacturers also vary the color and the texture or pattern on thefront face of the block. It might be desirable for the face of the blockto be smooth, serrated, or grooved or to have an aggregate appearance.

Creating a random, or ashlar, pattern in the face of a wall is highlydesirable. This gives the appearance of a mortared or dry-stackednatural stone wall, which is a traditional and well accepted look. Somecurrent wall blocks are intended to create an ashlar pattern. However,the creation of a truly random appearance requires the production ofmultiple block shapes for use in a single retaining wall. This isinefficient from a production standpoint because this requires multiplemolds and more kinds of blocks to inventory. If only one face of theblock is intended to be the front face, then the block system willsuffer a trade-off between having enough face sizes to create a random,natural appearance and the cost and inefficiency of using multiple moldsand creating multiple inventory items.

The shape of the block is also an important feature during installationof a retaining wall. Forsberg '876 illustrates a fairly complex shapefor a retaining wall block which is particularly advantageous in theconstruction of curved walls. The block is symmetrical about a verticalplane which bisects the block at a midway point through the front andback faces.

Many commercially available blocks are symmetrical about a planebisecting the front and back surfaces. Typically such blocks have planesrather than axes of symmetry, as there are differences between the topand bottom surfaces of such blocks. Clearly, blocks that aresubstantially square or rectangular (i.e., each surface being joined toanother at an orthogonal angle) exhibit a great deal of symmetry. Otherblocks are more complex in shape and exhibit only one vertical plane ofsymmetry. For example, U.S. Pat. No. 5,711,130 (Shatley) illustrates ablock having substantially parallel front and back faces andnon-parallel, mirror-image side wall surfaces. That is, there is amirror plane of symmetry that vertically bisects the block. U.S. Pat.Nos. 5,598,679 (Orton et al.) and 5,294,216 (Sievert) illustrate a typeof block having parallel front and back faces and non-parallel,converging side surfaces. The term “converging side surfaces” means thatthe side walls of the blocks converge as they approach the rear of theblock. Such blocks are also symmetrical about a vertical plane thatpasses through the front and back surfaces.

There are advantages to having non-parallel surfaces on these blockswhen constructing a retaining wall. The angles formed by these sidesurfaces permits construction of curvilinear walls, and moreover, permitthe amount of curvature to vary according to the terrain and desiredappearance of the wall.

However, problems still remain in the field of retaining walls and freestanding walls. Easy-to-use methods and systems that result in safe,stable and cost effective walls are continually sought.

It would be desirable to have a system of blocks for constructing a wallthat combines the ability to improve the reinforcement of the wall withthe ease of installation of modern segmental walls, while stillproviding for an attractive appearance of a natural stone wall. Theblock system should allow the construction of retaining walls,freestanding walls, straight walls, and curved walls.

SUMMARY OF THE INVENTION

The present invention relates to blocks and methods of constructingretaining walls, freestanding walls, straight walls, curved walls andcircular walls with the blocks. The blocks have a first face which has alarger surface area than a second face and the blocks may have a sideconnection system wherein the side of the block is provided with achannel or slot that is configured to engage a corresponding projectionon an adjacent block. There may be one or more channels or slots andcorresponding projections on the block. A different embodiment of theblock provides an alternate side connection system wherein the sides ofthe block are provided with channels or slots and are configured toalign with a channel or slot of an adjacent block forming a connectionreceiving cavity wherein connectors are received. The blocks may also beprovided with circular cores and cavities which overlap in adjacentcourses of a wall to form vertical cavities inside the wall. Thesevertical cavities may be filled with a stabilizing material and alongwith the side connection system give the wall additional stability, notonly between blocks of a course, but also between blocks in adjacentcourses.

In one aspect the present invention is a wall block for use in forming awall from multiple wall blocks, the wall having a front surface and arear surface, the wall block including opposing and parallel upper andlower planar surfaces spaced apart to define a block thickness; opposingand parallel first and second faces spaced apart to define a blockdepth; and opposing first and second side surfaces spaced apart todefine a block width, the first and second side surfaces together withthe upper and lower surfaces and the first and second faces defining ablock body, the first and second side surfaces converging from the firstface to the second face such that a width of the block at the first faceis greater than a width of the block at the second face, the block bodyhaving a circular core extending between the upper and lower surfaces,the core having a radius r, each of the first and second side surfaceshaving a curvilinear recess having a radius of curvature r′, where requals r′, each of the side surfaces further having at least one slotextending between the upper and lower surfaces and at least oneprojection extending between the upper and lower surfaces. The wallblock further includes the block body being configured such that whenthe wall is constructed from a plurality of the wall blocks arranged inmultiple courses in a running bond pattern, the front surface of thewall may be constructed from either the first or second faces of theplurality of wall blocks or a combination thereof, curvilinear recessesof adjacent blocks in a course form an opening which aligns verticallywith cores in blocks in adjacent courses and the at least one projectionof blocks in a course are received in the at least one slot of adjacentblocks of the course.

The wall block may further include at least one of the first and secondfaces being textured and at least one of the first and second faces hasa beveled perimeter while including side surfaces that may not betextured. The r and r′ of the wall block may be in the range of 1½inches to 2 inches. The slots and projections of the wall block may havea cross-sectional shape which is selected from curvilinear andrectilinear.

In another aspect the present invention is a wall block system for usein forming a wall from multiple wall blocks, the wall having a frontsurface and a rear surface, the wall block including a plurality ofblocks including first and second blocks, each block having opposing andparallel upper and lower surfaces spaced apart to define a blockthickness, opposing and parallel first and second faces spaced apart todefine a block depth, opposing first and second side surfaces spacedapart to define a block width, the first and second side surfacestogether with the upper and lower surfaces and the first and secondfaces defining a block body, each of the side surfaces having at leastone slot extending between the upper and lower surfaces, the slotdefining a longitudinal opening at the side surface and an interiorcavity, the interior cavity having a width which is greater than a widthof the opening of the slot. The wall block also includes a plurality ofelongate connectors including a first elongate connector, each elongateconnector having first and second end portions and an intermediateportion, the first and second end portions being configured such thatwhen the wall is constructed from a plurality of the wall blocksincluding the first and second wall blocks arranged side-by-side in acourse of blocks the first end portion of the first elongate connectoris accommodated within a cavity of the first block and the second endportion of the first connector is accommodated within a cavity of thesecond block to thereby lock the first and second blocks together in thewall.

The wall block system may further include at least one of the first andsecond faces of the wall block being textured and at least one of thefirst and second faces having a beveled perimeter while including sidesurfaces that may not be textured. The plurality of elongate connectorsof the wall block system may be bow-tie shaped in transversecross-section and the end portions of the plurality of elongateconnectors may have laterally extending projections. The first andsecond side surfaces of each block of the wall block system may alsoconverge from the first face to the second face such that a width of theblock at the first face is greater than a width of the block at thesecond face.

The block body of each block of the wall block system may also include acircular core extending between the upper and lower surfaces, the corehaving a radius r and the first and second side surfaces of each blockmay additionally have a curvilinear recess having a radius of curvaturer′. The wall blocks of the wall system may also have r equal to r′ andmay be in the range of 1½ inches to 2 inches.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B illustrate perspective and bottom views respectively, ofa first embodiment of a first wall block of this invention.

FIG. 1C illustrates a perspective view of an alternate embodiment of thefirst wall block of this invention.

FIG. 1D is a perspective view of a portion of a wall constructed withthe block of FIGS. 1A and 1B.

FIGS. 2A and 2B illustrate perspective and bottom views respectively, ofa first embodiment of a second retaining wall block of this invention.FIG. 2C illustrates a perspective view of a block connector used in awall system constructed of the wall block of FIGS. 2A and 2B.

FIG. 3 is a top view of a curvilinear wall made with the wall blocks ofFIGS. 1A and 1B.

FIG. 4 is a top view of a straight wall made with the wall blocks ofFIGS. 1A and 1B.

FIG. 5 illustrates a top view of a curvilinear wall made with the wallblocks of FIGS. 2A and 2B.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In this application, “upper” and “lower” refer to the placement of theblock in a wall. The lower or bottom surface is placed such that itfaces the ground. In a wall, one row of blocks is laid down, forming acourse. An upper course is formed on top of this lower course bypositioning the lower surface of one block on the upper surface ofanother block. If the blocks in each course are vertically aligned toform parallel vertical columns of blocks the resulting wall has astacked bond pattern. If the blocks in each course are vertically offsetthe wall has a running bond pattern.

This invention comprises blocks that are used together in theconstruction of a wall. The blocks are configured to be compatible witheach other in the construction of a retaining wall, a parapet wall, anda free-standing wall. Such walls may be straight, curved, or circular.Although not a requirement of this invention, each block may have atleast one face that is textured in a manner resulting in the appearanceof natural stone. When at least two faces of the block have beentextured, the orientation of the faces may be reversed so that eitherthe front or the back of the block may serve as an exposed face.Preferably, there is a natural-appearing finish on all exposed sides ofthe wall. The wall system is designed to be structurally sound and easyto install. The wall system is especially useful in constructing smallerwalls having a height of about 3 feet or less.

Blocks may also be provided with a side connection system wherein a sideof the block is provided with a channel or slot that is configured toengage a corresponding projection on an adjacent block. There may be oneor more channels or slots (and corresponding projections) on the block.Typically, and preferably, the side connection system is used on asmooth, untextured side of the block. The side connection system is aparticular advantage in the construction of free-standing walls. This isbecause the side connection further stabilizes the wall and because theslots and projections prevent light from showing through the wall andtogether provide for a close fit of the blocks in the wall.

FIGS. 1A and 1B illustrate a first embodiment of a first block 100 a ofthis invention. FIG. 1D is a perspective view of a portion of a wallconstructed with blocks 100 a. Block 100 a comprises lower surface 104opposed and substantially parallel to upper surface 102, and opposingand substantially parallel first and second (also referred to as frontand back) faces 106 a and 108 a, respectively. The upper and lowersurfaces are separated by the thickness of the block. For the purposesof this description, first face 106 a is shown facing the viewer in FIG.1A, however, it is to be understood that the first faces of some blocksand second faces of other blocks are in some situations exposed on thesame side of a wall interchangeable when the blocks are used in a wall,for example, as will be described in connection with FIG. 4. The blockalso comprises opposing and converging side surfaces 110 and 112 (i.e.,imaginary lines coincident with side surfaces 110 and 112 willeventually converge at some distance away from the second face or backof block 100 a) and are separated by the width of the block. Theconverging side surfaces result in first face 106 a having a largersurface area than second face 108 a. Side surfaces 110 and 112 havecurvilinear recesses 114. Block 100 a is shown with lower surface 104facing up and upper surface 102 facing down in FIG. 1B, however it is tobe understood that either the upper surface or the lower surface couldbe used as the top surface of the blocks when constructing a wall formthe blocks. Block 100 a is provided with core 116 that extends throughthe thickness of the block. Preferably core 116 is circular.

Block 100 a can be sized to desired dimensions. For example, thethickness of the block can be 4 inches (10.2 cm), the width of the blockcan be 12 inches (30.5 cm) along a first face 106 a and 9⅜ inches (23.8cm) along the second face 108 a and the depth of the block between thefirst and second faces can be 7¾ inches (19.7 cm). The circular core hasa radius r and curvilinear recesses have a radius r′. Preferably requals r′. Typically r and r′ will be in the range of 1½ inches (3.8 cm)to 2 inches (5.1 cm).

Utilizing a generally circular core 116 has been found to provideseveral advantages. A circular core which forms a cylindrical openingthrough the block can be made quite large in comparison to the totalblock dimensions without compromising the strength of the block. Furthera circular core does not result in the existence of sharp angles beingformed within the structure of the block which are more likely to break.Still further, the combination of a circular core and curvilinear siderecesses provides an advantage when constructing a wall with a pluralityof the blocks. The curvilinear recesses of adjacent blocks in a courseof the wall form a cavity with a curvilinear perimeter which may besubstantially circular. This cavity aligns with the circular cores ofblocks in courses above and below when the wall is constructed in arunning bond pattern. This results in the formation of a plurality ofvertical columnar cavities from the top of the wall to the bottom of thewall. The circular shape of the cores and the curvilinear shape of therecesses minimize any overlapping edges in the cavity which could blockstabilizing fill material from filling the cavity as discussed below.

Block 100 a is provided with a side connection system wherein a side ofthe block is provided with a channel or slot that is configured toengage a corresponding projection on an adjacent block. Side surface 110has projection 111 a located proximate to second face 108 a and slot 113a located proximate to first face 106 a. Side surface 112 has projection111 b located proximate to first face 106 a and slot 113 b locatedproximate to second face 108 a. The shape of the projection and slot areshown as being curvilinear, however it is to be understood that theshape could be rectilinear or another shape. First blocks of thisinvention could also have both slots located on one side and bothprojections located on the other side. The block may also be configuredto have only one slot/projection on each side or may also be configuredto have more than two. Typically, and preferably, the side connectionsystem is used on a smooth, untextured side of the block. This allowsfor a close fit and tight connection between adjacent blocks as morefully described in connection with FIGS. 3 and 4. The side connectionsystem is a particular advantage in the construction of free-standingwalls. This is because the side connection further stabilizes the walland because the slots and projections prevent light from showing throughthe wall and together provide for a close fit of the blocks in the wall.

FIG. 1C illustrates an alternate block embodiment. Block 100 b asillustrated in FIG. 1C is substantially similar to block 100 a. Firstand second faces 106 b and 108 b have been given a beveled perimeter 109b and a notch 107 b. It is to be understood that the bevels 109 b andnotch 107 b could be placed on one or both of the faces. It is also tobe understood that the faces may be given just the bevels or just anotch and not a combination of both features. The bevels and notchprovide for the formation of a multisized and random block pattern onthe exposed wall surface. In an alternate block embodiment faces of theblock could also be given an imprinted texture. It is to be understoodthat the imprinted texture could be placed on one or both of the faces.

FIGS. 2A and 2B illustrate a first embodiment of a second block of thisinvention. Block 200 comprises lower surface 204 opposed andsubstantially parallel to upper surface 202, and opposing andsubstantially parallel first and second (also referred to as front andback) faces 206 and 208, respectively. The block also comprises opposingand converging side surfaces 210 and 212 (i.e., imaginary linescoincident with side surfaces 210 and 212 will eventually converge atsome distance away from the back of block 200) and are separated by thewidth of the block. The converging side surfaces result in first face206 having a larger surface area than second face 208. Side surfaces 210and 212 have curvilinear recesses 214. Block 200 is shown with lowersurface 204 facing up and upper surface 202 facing down in FIG. 2B,however it is to be understood that the upper and lower surfaces areinterchangeable when used in a wall. The upper and lower surfaces areseparated by the thickness of the block. Block 200 is provided with core216 that extends through the thickness of the block.

Block 200 is provided with a side connection system wherein the sidesurfaces 210 and 212 of the block are provided with at least one channelor slot 215 and are configured to align with a corresponding channel orslot on an adjacent block. As best seen in FIG. 5 this alignmentproduces a connector receiving cavity 218 that is configured to receivea connector 50 as shown in FIG. 2C. Connector 50 has a bow-tie shapewith a number of friction projections 54 located on the shaft 52. Thesefriction projections increase the surface area of the connector and helpto secure the connector into the cavity, thus reducing the amount ofmovement of the blocks relative to one another. The connector may be aninjection molded part made of a compressible material such as plastic.The compressible material should not be brittle but pliable to enable afirm compression friction fit of the connector into the connectingcavity. This will lock the blocks together yet enable adjacent blocks tobe flexible and somewhat moveable with respect to each other which is anadvantage if there is any movement or slanting of the wall. It should benoted that this side connection system could be used on other types ofwall blocks and wall block systems for constructing various walls andother structures.

The blocks of either embodiment are made of a rugged, weather resistantmaterial, preferably (and typically) zero-slump molded concrete. Othersuitable materials include wet cast concrete, plastic, reinforcedfibers, wood, metal and stone. Blocks of this invention are typicallymanufactured of concrete and cast in a masonry block machine. Theblock's dimensions are selected not only to produce a pleasing shape forthe wall, but also to permit ease of handling and installation.Providing a large core (i.e., large relative to the overall block size)is preferred because it results in a reduced weight for the block, thuspermitting easier handing during installation of a wall.

FIG. 3 illustrates a circular wall made with wall block 100 a of thepresent invention. Generally, when constructing a wall a trench isexcavated to a pre-selected depth and lined with a level base ofgranular material such as crushed stone. A base layer is then placed andleveled unto the crushed stone. The blocks are placed side to side withfirst face 106 a facing outward. The adjacent block is placed and theprojection and slot of the side of one block fits securely into the slotand projection of the adjacent block. This interlocks adjacent blocks ina course giving the wall more stability without the use of pins and pinreceiving apertures typically found in prior art block systems. Once thebase layer is laid, subsequent layers are placed one on top of the nextuntil the desired height is reached. Once the desired height is reacheda capping layer may be added. Typically, the placement of blocks arevertically offset in adjacent courses in a running bond pattern.Curvilinear recesses 114 of side surfaces 110 and 112 form substantiallycircular cavities 117 when laid side to side and are substantiallysimilar in size and shape to core 116. The cores and cavities overlapone another in adjacent courses producing vertical columnar cavitiesinside the wall structure. The circular shape of the cores and cavitieshelps to maximize the alignment and functional volume of the verticalcavity. These columnar cavities may be filled with a stabilizingmaterial such as sand, gravel, sheer resistant fill (i.e. crushedstone), concrete, cement or the like, to give the wall added stability.The interlocking projections and slots along with the stabilizingmaterial added to the vertical columnar cavities stabilize the wallmaking it structurally sound without the use of traditional stabilizingsystems such as pins and the like. Optionally, construction adhesive maybe used to lack blocks and/or courses together with or without the useof stabilizing materials.

FIG. 4 illustrates a straight wall made with wall blocks 100 a of thepresent invention. A straight wall is produced by alternating theplacement of the first and second faces of blocks relative to eachadjacent block (i.e. first face 106 a of a block is placed projectingoutward and then the second face 108 a of an adjacent block is placedprojecting outward). The adjacent block is placed and the projectionsand corresponding slots of each block secures the blocks to one another.This interlocks the blocks together giving the wall more stabilitywithout the use of pins and pin receiving apertures.

FIG. 5 illustrates a circular wall made with block 200 of the presentinvention. A trench is excavated to a pre-selected depth and lined witha level base of granular material such as crushed stone. A base layer isthen placed and leveled unto the crushed stone. The blocks are placedside to side with first face 206 facing outward. When adjacent blockshave been laid side to side, slots 215 of each adjacent block align andform connector receiving cavity 218. Connector 50 is then placed intothe cavity 218 securing the side of one block to the adjacent side of asecond block. Curvilinear recesses 214 of side surfaces 210 and 212 formcavities 217 when laid side to side and are substantially similar insize and shape to core 216. The cores and cavities overlap on anotherwith each staggered course producing vertical columnar cavities insidethe wall structure. These columnar cavities may be filled with astabilizing material such as sand, gravel, sheer resistant fill (i.e.crushed stone), concrete cement or the like to give the wall addedstability. The connectors and connector cavities form a side connectionsystem. This system along with the stabilizing material added to thevertical columnar cavities supports the wall making it structurallysound.

Although particular embodiments have been disclosed herein in detail,this has been done for purposes of illustration only, and is notintended to be limiting with respect to the scope of the claims. Inparticular, it is contemplated that various substitutions, alterations,and modifications may be made to the invention without departing fromthe spirit and scope of the invention as defined by the claims. Forinstance, the choice of materials or variations in the shape or anglesat which some of the surfaces intersect are believed to be a matter ofroutine for a person of ordinary skill in the art with knowledge of theembodiments disclosed herein.

1. A wall block for use in forming a wall from multiple wall blocks, thewall having a front surface and a rear surface, the wall blockcomprising: opposing and parallel upper and lower planar surfaces spacedapart to define a block thickness; opposing and parallel first andsecond faces spaced apart to define a block depth; opposing first andsecond side surfaces spaced apart to define a block width, the first andsecond side surfaces together with the upper and lower surfaces and thefirst and second faces defining a block body, the first and second sidesurfaces converging from the first face to the second face such that awidth of the block at the first face is greater than a width of theblock at the second face, the block body having a circular coreextending between the upper and lower surfaces, the core having a radiusr, each of the first and second side surfaces having a curvilinearrecess having a radius of curvature r′, where r equals r′, each of theside surfaces further having at least one slot extending between theupper and lower surfaces and at least one projection extending betweenthe upper and lower surfaces; and wherein the block body is configuredsuch that when the wall is constructed from a plurality of the wallblocks arranged in multiple courses in a running bond pattern, the frontsurface of the wall may be constructed from either the first or secondfaces of the plurality of wall blocks or a combination thereof,curvilinear recesses of adjacent blocks in a course form an openingwhich aligns vertically with cores in blocks in adjacent courses and theat least one projection of blocks in a course are received in the atleast one slot of adjacent blocks of the course.
 2. The wall block ofclaim 1 wherein at least one of the first and second faces is textured.3. The wall block of claim 1 wherein the side surfaces are not textured.4. The wall block of claim 1 wherein r and r′ are in the range of 1½inches to 2 inches.
 5. The wall block of claim 1 wherein the slots andprojections have a cross-sectional shape which is selected fromcurvilinear and rectilinear.
 6. The wall block of claim 1 wherein atleast one of the first and second faces has a beveled perimeter.
 7. Thewall block of claim 1 wherein the first side surface has one slot andone projection and the second side surface has one slot and oneprojection.